The existing annotation pipeline could not handle such cases out of the
box; as a result, the original design has been stretched in order to
accommodate the new use cases, leading to a brittle and hard-to-maintain
implementation. The goal of this work is to replace this aging
architecture with a new one which supports the new use cases in a more
straightforward fashion, leading to more-correct and maintainable code.

Description

Refactor the javac annotation pipeline. This should not be externally
noticeable except where we fix bugs and improve correctness. The first
step is to improve testing coverage so we can measure and evaluate our
exit criteria. After that follows a series of incremental
refactorings. This work will be done in the OpenJDK
Annotations Pipeline 2.0 Project.

The javadoc tool has some related issues with regards to type
annotations. javadoc is, however, undergoing significant work as part of
the Javadoc.Next Project.
Part of that work includes converting javadoc to use the
javax.lang.model API instead of the older com.sun.javadoc
API. It is, therefore, not a goal of this project to work on javadoc to
ensure that annotations, including type annotations, are presented
correctly. It is expected that, as part of the JavaDoc.Next Project,
javadoc will be enhanced to leverage the updates to the
javax.lang.model API that are a goal of this project.

Testing

There is already good coverage of a substantial set of end-to-end use
cases of annotations. This includes JCK and langtools regression tests.
A big part of this work is to develop further tests to ensure the
measurability of the success metrics.

We will create tests that exercise the intersection of the new features
in Java SE 8, as mentioned above.